Update- the temperature climbed to 38.8C here on 19th July. All ten swift chicks and six house martin chicks are fine.
I was woken early (4.45am) by eager non-breeding swifts. The adult breeders had already left the nest boxes. There was a delightful coolness in the garden- we were fortunate, after yesterday’s 36.2C heat that the temperature fell to 13C overnight. We have had much warmer nights but we have not had hotter days, ever.
There is plenty of commentary on the science behind this weather and its destructive effect on humans and the natural world. Suffice to say this is a temperature I hoped I would not see, but what else could I do but observe the swift and house martin behaviour in such conditions?
Watercolour does not behave well in this heat. It dries, almost instantly, so the challenge of moving the paint fast saw me drawing very quickly with the brush. An advantage perhaps as observation had to be fast and sharp.
I watched the swifts at first in warm early morning temperatures and knew what to expect as time went on. At what point I wondered, would they start dangling their feet to expose their toes to cooling airflow. I have seen this many times before and always thought that when the temperature reached 28C the first swifts become foot danglers! It proved to be exactly so this morning, then as the temperature continued its brutal rise more and more swifts dangled. I also noticed house martins and tree sparrows doing the same. This was something I was very keen to sketch. Gradually a sheet of studies emerged- as seen below. It gives a snapshot of swift and house martin behaviour on the hottest day in UK recorded history.
Fortunately three out of five house martin pairs have fledged young. They fed high early on, probably not a bad start for these recent fledglings. But below in their baking nests the remaining nestlings panted and gasped for air at the entrance. Swift nestlings seemed to ride it out by keeping largely very still. They spread out in the nest boxes. I have to hope that they make it through the rest of the day before finally cooler temperatures arrive.
The hot weather has brought me undeniable pleasure watching swifts. They perform effortlessly, fuelled by abundant food. I have relished seeing very fast, low passes inches from my face and seen year old birds throwing themselves at the eaves. A new nest box has been entered and others peered into another box giving hope for a further increase at the colony in 2023. So I have accepted this weather for what it is and produced the watercolour below- a sheet of observations on a historic day of weather.
I must mention the skilled rehabilitation workers especially our own Northern rehabbers Linda Jenkinson of Leeds Swifts and Start Birding and Louise Bentley of Bolton and Bury Swifts. They make huge sacrifices and work crazy hours to release healthy swifts and house martins. My thoughts are very much with them as they battle to save lives in this heat. Thank you swift and house martin carers everywhere.
All text and images copyright Jonathan Pomroy 2022